Sheet feeding arrangements



.June 19, 1956 l. H. N. WATTON ET AL 2,751,224

SHEET EEEDING ARRANGEMENTS 3 Sheets-Sheet l Filed March 2'?, 1953 a/ NM/""Ill'llunhwll" Illlll.:

June 19, 1956 L. H. N. WATTON ETAL 2,751,224

SHEET FEEDING ARRANGEMENTS Filed March 27, 1953 3 Sheets-Sheet 2 Y #froleys E June 19, 1956 L. H. N. WATToN ET Al. 2,751,224

SHEET FEEDING ARRANGEMENTS Filed March 27, 1955 3 Shets-Sheet 3 /nver/fins hm@ Zar/#naaf SHEET FEEDING ARRANGEMENTS Leonard HerbertNeville Watton, New Malden, and Roland Brown and Frederick William Hall,London, Engiand, assignors to Hall Telephone Accessories Lim* ited,London, England, and Block & Anderson Limited, London, England, bothBritish companies Application March 27, 1953, Serial No. 345,042 Claimspriority, application Great Britain March 31, 1952 6 Claims. (Cl.271-43) This invention relates to arrangements for feeding sheets (whichterm is to be understood to include also like articles such asenvelopes) from a stack to a printing, duplicating or other sheethandling machine. The invention is concerned more particularly witharrangements whereby a table carrying a stack of sheets can be adjustedautomatically so that the top sheet is at the correct level for beingfed from the stack to the sheet handling machine.

According to the present invention, the feed table is pivotally mountedat or near the end remote from that at which the sheet is delivered andprovision is made of means tending to urge the delivery end of the tablein an upward direction, the upward movement being arrested by meanscontrolled by a detector adapted to engage the surface of the uppermostsheet whereby the table is positioned with the said uppermost sheet atthe desired level for being fed from the feed table.

Preferably, the front face of the stack of sheets is registered againsta front plate extending downwardly from slightly below the feeding leveland lying in a plane which is substantially tangential to the curvedsurface described by the delivery end of the feed table at the line ofintersection of the feeding level with said curved surface. lf thesheets are stacked against the front plate when the delivery end of thefeed table is in a depressed position, the sheets are progressivelypressed back by a small amount as the feed table rises, thereby ensuringa constant position of the topmost sheet on the feeding level.

Conveniently, the motive power for lifting the table is provided by oneor more springs which are tensioned by the act of depressing the table.To regulate the speed of rise of the table under the spring action agovernor such as a pendulum-controlled escapement may be provided. Thegovernor may be associated with the sheet detector in such manner thatthe table is locked not only when the top sheet is in the desiredfeeding level but also when the sheet detector is displaced out of itsnormal sheet-detecting position.

lf the sheets are fed from the table by a combing roller carried on apivotal arm, this feed roller may also serve as sheet detector, therising motion of the table being arrested when the feed roller is lifteda short distance by the table. The rising motion may also be arrestedwhen the feed roller is pivoted away from the table into an idleposition.

Instead of the motive power for lifting the table being derived fromenergy stored by the act of depressing the table into a loadingposition, the motive power may be derived from a moving part of thesheet handling machine, such as the printing drum of a hectographiccopying machine, which may be electrically or manually operated.

More particularly when a combing roller is employed to feed the sheetsfrom the feed table it is desirable to ensure that the feed action issuspended before the stack is exhausted, so that no damage resultseither to feed d 2,755 1,224 Patented `lune 19, 1956 ice roller or feedtable. For this reason, it is advantageous to provide an adjustable tripwhich when the table reaches a predetermined position, prevents furtheroperation of the machine. This can be done from a shaft geared to thelifting drive and adapted to trip the operation after the shaft hasturned through a predetermined angle. In an electrically driven machine,the trip may be associated with the usual trip for interrupting theoperation of the machine.

ln the accompanying drawings, which show a fragment of a duplicatingmachine in association with a sheetfeeding arrangement according to theinvention,

Fig. l is a side view showing the feed table empty,

Fig. 2 is a corresponding view with the feed table loaded,

Fig. 3 is an enlarged side view of the escapement controlling the risingmovement of the feed table,

Fig. 4 is an end view of Fig. 3,

Fig. 5 is a section substantially along the line V-V of Fig. 3, and

Fig. 6 shows a detail.

The side frames of the machine, one of which is indicated at 1, eachcarry a rearwardly extending arm (not shown), the rear ends of which aresecured to a xed bracket 2 providing a pivot 3 on which are pivoted dependent arms 4 rigidly secured to the sides of the feed table 5 at itsrear end. The feed table 5, which is thus pivotally supported at 3, isprovided in the usual Way with at least one side guide 6 which isadjustable laterally of the machine and is secured in position by areleasable locking lever 7. The sheets to be fed may be disposed betweena pair of such side guides, each provided with a friction padaccommodated within a housing 8 on the side guide and bearing againstthe edges of the sheets with a pressure adjustable by a screw adjustmentindicated at 9. Rigidly mounted on the side frames of the machine at thefront end of the feed table 5 is a plate 10 having a downwardlyextending portion 101.

The sheets positioned on the feed table 5 (see Fig. 2) are fed to themachine by means of a combing roller 11 which in its operative positionrests on the top sheet and is driven to advance this sheet from the pileof sheets to the machine. The combing roller 11 is carried in an arm 12pivotally mounted at 13. Means for driving such a combing roller to feedthe top sheet to the machine are well known and consequently are notshown and will not be described.

The front end of the feed table 5 is supported from below by a roller 15journalled at the end of one arm 14 of a bell crank lever which issecured on a shaft 16 and the other arm 17 of which is secured to atension spring 18, the other end of which is anchored to the side frame1 at 19. Preferably the bell-crank and spring arrangement is duplicatedat the other side of the machine, so as to provide a symmetricalmechanism. lt will be apparent that when a pile of sheets is placed onthe feed table 5 and the feed table is depressed at its front end tobring the top sheet to the level of the plate 10, the bell crank arm 14is depressed and the arm 17 is moved away from the anchor 19 against theaction of the spring 18. The spring 18 thus tends to urge the table 5upwardly.

The escapement mechanism which is shown in greater detail in Figs. 3, 4and 5 is provided to control the upward movement of the feed table 5under the action of the spring 18. Secured on the shaft 16 (Figs. l and2) is a gear wheel 20 meshing with a gear wheel 21 secured on a shaft 26which carries a further gear wheel 22. The wheel 22 meshes with a gearwheel 23 fast on a shaft 27. Loose on the shaft 27 but coupled therewithby means of a uni-directional coupling such as a dog clutch is a furthergear wheel 24. The wheel 24 meshes with a gear wheel 25 secured on ashaft 28 to which is also secured an escapement wheel 29. The rotationof the escapement wheel 29 is controlled by a rocker 30 to which isattached a pendulum arm 31 carrying a pendulum weight 32. When thependulum 31,` 32 is free to swing, its natural frequency determines therate of movement of the escapement wheel 29. The gear train 20-25 givesa predetermined step-down ratio and permits a correspondingly reducedrate of movement of the shaft 2,6 and thus determines the upwardmovement imparted to the table by bell crank 14 and roller 15. Theunidirectional coupling between shaft 27 and gear wheel 24 permits thetable 5 to be depressed by the operator for loading at any desired rateindependent of the pendulum control.

To arrest the upward movement of the feed table 5 when the top sheet isat the appropriate level, means are provided for locking the escapementrocker 30. For this purpose, the rocker 30 carries an upwardly extendingpin 33. This pin is adapted to be embraced by the free end of an arm 34pivoted at 35 and controlled by a link 36. The link 36 is permitted tomove lengthwise and is guided by a fixed pin 38 engaging in a slot 37.It will be apparent that when the link 36 is allowed to move downwardly,the arm 34 engages the pin 33 and holds the rocker 3ft. The link 36 iscontrolled by a detector responsive to the position of the top sheet ofthe pile. In the construction shown, this detector is constituted by thecombing roller 11. An arm 40 secured to the pivotal arm 12 carrying theroller 11 is adapted to engage a pin 39 on the link 36, so that if theroller 11 drops below the level of the plate the arm 40 engages the pin39 to lift the link 36 and with it the arm 34. The pin 33 is therebyreleased and the drive of the spring 18 is operative to raise the feedtable 5 until the roller 11 is raised by the pile of sheets sutiicientlyto allow the link 36 to drop to lock the escapement.

To facilitate the loading of the feed table, the arm 12 carrying theroller 11 is adapted to be raised into and latched in the position shownin Fig. l. For this purpose the arm 40 carries a star-shaped` latch 41which normally slides over a part circular guide in a plate 42. Thelower end of the guide terminates in a recess 43 in which the latch 41engages to hold the arm 12 in the raised position. On lifting the arm 12slightly from the raised position, the latch 41 is rotated clockwisefrom the position shown in Fig. l and it is then able to enter thecircular part of the guide plate 42. The escapernent 30 is locked exceptwhen the roller 11 is in the desired sheet-feeding position.

As shown in Figs. l and 2, the downwardly extending part 101 of theplate 10 slopes away from the front end of the feed table S. Thus whenthe table 5 rises from its depressed position the pile of sheets isslightly displaced rearwardly in its movement over the plate 161, thusensuring that slight irregularity in the stacking or positioning of thepile on the table S does not affect the position from which the feed ofthe top sheet commences. This pre-registration prior to the commencementof the feed movement facilitates the achievement of accurateregistration in the subsequent feeding of the sheet.

if, when using a combing roller 11, as shown, it is desired to preventthe upward movement before the stack is exhausted, so that no damageresults either to feed roller 11 or feed table 5, the shaft 16 may beprovided with an adjustable trip which when the roller 1.5, and thus thetable 5, reaches a predetermined position prevents further operation ofthe machine, i. e. when the shaft 16 has turned through a predeterminedanglel from a position corresponding to maximum load position. If themachine is driven electrically, the trip may be associ. ated withconventional trip meansA for interrupting the operation of the machine.Such an arrangement is shown in Fig. 6 which represents a detail view onthe opposite side of the machine to Figs. l and 2. In Fig. 6, the arm 44secured on the shaft 16 carries a pin 45 which engages in a slot 46 in alink 47 the other end of which is pivotally connected to a lever 48mounted on a pin 49 on the side frame of the machine. The lever 48engages a trip member 56 adapted to release a clutch in the drivemechanism. Such trip-controlled clutch arrangements are well known inpower-driven duplicating and like machines and consequently are neithershown nor described in the present specification. it will be apparentthat the pin-and-slot arrangement 45, 46 forms a post-motion whichpermits the shaft 16 to perform a movement up to a predetermined settingbefore the trip is actuated. Adjustment may bc effected by altering theiength of the link 47 and/or providing an adjustable eccentric portionon the trip member 5i) for engagement with the lever 48.

We claim:

1. A sheet feeding arrangement comprising a feed table pivotally mountedat or near the end remote from that at which the feed sheet `isdelivered, spring means tending to urge the delivery end of the table inan upward direction, a shaft on which said spring means acts tending torotate said shaft, means associated with said shaft for lifting saidtable by the rotation under the spring action, an escapement wheel on afurther shaft positively geared to said first shaft so as to rotatetherewith, an oscillatory escapement member cooperating with saidescapcment wheel and adapted to oscillate at a predetermined rate so asto regulate the rotation of said escapernent wheel and thereby toregulate the rate of rise of said feed table under the action of saidspring means, a detector located in position to engage the surface ofthe uppermost sheet, and locking means controlled by said detector andoperating on said escapement member to iock said escapement member toarrest the upward travel of the delivery end of the table when it ispositioned with the uppermost sheet at the desired level for being fefrom the feed table.

2. A sheet feeding arrangement as claimed in claim l, and in which theescapemcnt is a pendulum-controlled escapernent.

3. A sheet feeding arrangement as claimed in claim l, and in which thesheets are fed from the feed table by a combing roller carried by apivotal arm and the combing roller is also utilised as the detector inthat the angular movement of the pivotal arm is employed to control thelocking means.

4. An arrangement according to claim l, and in which the spring meansare constituted by a spring which is tensioned by the act of depressingthe table.

5. An arrangement according to claim l and in which the front face of astack of sheets is registered against a downwardly extending plate sodisposed that if the sheets are stacked against the front plate when thedeiivcry end .is in a depressed position the sheets are progressivelypressed back as the feed table rises, substantially as and for thepurpose hereinbefore set forth.

6. An arrangement according to claim 1, and in which means are providedto prevent further upward movement of the feed table at a predeterminedposition such that the stack of sheets on the table is not exhausted.

References Cited in the tile of this patent UNITED STATES PATENTS218,355 Young Aug. 5, 1879 672,043 Sheckler Apr. 16, 1901 1,914,849Davidson .Tune 2Q, 1933 1,960,482 Duncan May 29, 1934 1,989,911 BrasseurFeb. 5, 1935 2,167,477 Gluny July 25, 1939 2,472,441 Schmitt June 7,1949

